My week old kentia has some stems developing brown spots. Is this an infestation? Plant is acclimatizing to its new home and is developing some brown tips but otherwise healthy

That does not look normal to me. Will it wipe off?

Wiping off with a wet tissue takes away reddish brown fuzz from the stem but leaves behind the darker dots

It's called "tomentum" a natural fuzzy hair fiber growth on petioles. Just look at the fuzz on this Trachycarpus Takil even on the ligule area.

Also note the lack of long strappy ligules common with fortunei.

Trachycarpus takil has very short l which split in a short triangular pattern.

back to the subject, your palm is fine in fact the tomentum souls Apartments happy and growing